Cirrus Logic CS6422 - Manual (Page 23)

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3.6.1 TSATT - TRANSMIT SUPPRESSION ATTENUATION
This parameter sets the amount of attenuation inserted into the transmit path when transmit suppres-
sion is engaged.
3.6.2 PCSEN- PATH CHANGE SENSITIVITY
The Acoustic Interface is likely to have many path changes as people move about in the room where
the full-duplex speakerphone is being used. The sensitivity of the path change detector can be
changed with the PCSen bit. Set PCSen to ‘0’ for high sensitivity and ‘1’ for low sensitivity.
In any adaptive echo cancelling system, there is a trade-off between hearing echo and remaining in
full-duplex when the acoustic path changes. When PCSen is set to ‘0’ for high sensitivity, the CS6422
will tend to drop to half-duplex in the event of a path change, preventing the far-end listener from hear-
ing echo as the adaptive filter adjusts to the new path.
When PCSen is set to ‘1’ for low sensitivity, the CS6422 will tend to remain in full-duplex during the
path change, and the far-end listener may hear some residual echo as the adaptive filter adjusts to
the new path.
3.6.3 TDBTS - TX DOUBLE-TALK SUPPRESSION ATTENUATION
This parameter controls the amount of attenuation that is added to the transmit channel during dou-
ble-talk, that is, when parties at both ends of the link are speaking simultaneously.
3.6.4 RDBTS - RX DOUBLE-TALK SUPPRESSION ATTENUATION
This parameter controls the amount of attenuation that is added to the receive path during double-talk.
3.6.5 TSTHD - TRANSMIT SUPPRESSION THRESHOLD
This parameter sets the ERLE requirement for discrimination between echo and near-end speech by
the transmit suppressor. See Section 4.1.4.1, “Transmit Suppression” for full details.
3.6.6 TSBIAS - TRANSMIT SUPPRESSION BIAS
This bias level affects the ease with which near-end speech may break-in or be attenuated by far-end
echo which causes the transmit suppressor to engage. See Section 4.1.4.1, “Transmit Suppression”
for full details.
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